Do not provide Click to Add feature in calendar

By default, the 'Click to Add' UI appears when a user mouses over any of the following areas in the calendar: 1) an unoccupied space of at least one row in the scheduling area in day/week view 2) the bottom of the events area in day/week view and 3) the bottom of a day in the month view. This setting allows you to disable the 'Click to Add' feature in the Calendar.